Category: lab

Tree rings are a good way to study past and present climate. They are proxy indicators of climate change, but can be used to study other climate events as well. You will need several handouts for this lab. The student handout is on this google doc. Note: There are a lot of regional-specific questions in this lab. You will need edit for your own tree cookies and region.

Finding Tree Cookies

Wood-shop or career-tech construction classes. We have wood-shop on campus and the teacher had a spare log and cut a bunch of tree cookies for me. Shout out to Leonard Friedman, woodshop teacher extraordinaire!

Find or buy a log and use a chainsaw to cut your own cookies.

Wait until after Christmas and use a discarded live (now dead) tree.

Ask a tree-trimming company for branches or trunks of trees they are removing.

A firewood company may sell you unsplit logs.

A local college or extension may have some tree cookies to loan.

These tree cookies are from a local pine and show evidence of insect infestation.

Other Supplies

Setting up the Lab

Prepare tree cookies by placing pins on some of the dark rings. This helps students identify and measure between rings. Reading rings is actually harder than it seems. Students (and teachers) have some difficulty with this. When they are counting the number of rings, tell them to ESTIMATE and do the best they can, because its difficult.

If you have hard wood, you may need to use a hammer and thumb tack to make hole before then putting in one of the other pins.Customize your pins based on your location. This tree cookie shows severe drought in CA in the pink, black and blue pins and some El Nino years earlier.

If you choose to protect the trees with varnish, I recommend flat varnish, because gloss or semi-gloss reflect overhead classroom lights and make counting more difficult (learned this the hard way)

Copy the paper tree cores on card stock or laminate for durability. That way you can use for multiple periods and multiple years.

Measuring a paper tree core.

Preserving Tree Cookies

If you want to preserve your tree cookies to use for a long time and also prevent bugs and pests, the following are directions from APES teacher Mark Case: “I make tree cookies regularly. Step 1: soak the cookie in antifreeze for about a week. Make sure it is very well penetrated. Eggs and larva die. Step 2: Freeze for 72 hours in a deep freeze. Step 3: use a solar dryer. Any type tote and a piece of glass or plexi glass over the top in the hot summer sun. Step 4 let it dry for at least a week before you coat it with poly. “

AP® is a trademark registered and/or owned by College Board, which was not involved in the production of, and does not endorse this site.

I recently experimented using LED tap lights as an alternate to using stereoscopes in the Airborne Particulate Lab. You can read about the lab on this post. This is a great lab for kids to practice experimental design.

Students need to focus on the vaseline above the grid. If they focus on the graph paper, they won’t see any particulates. They need to hold the hand lens about 3-4 centimeters above the petri dish. That way it focuses on the particulates.

This method does work, but it takes a little more practice from the kids to see the particulates.

Engage: Flint, Michigan

This Engage is a short case study about lead exposure for students. Most students have heard of Flint, Michigan and its water quality problems so this adds to previous knowledge (a key component of Engage). The video piques their interest and then we discuss our own drinking water and how this problem would not occur here, because we are a newer community that does not have lead pipes. We also discuss how older cities with lead pipes can prevent lead leaching by using an additive in the water. Click to read this article explaining more about how lead gets into drinking water.

Explore: Serial Dilution

Students in AP® Environmental Science need to understand how toxins can still be prevalent in very small amounts. The best way to do this is for students to do a serial dilution. (Note: This activity is courtesy of Dan Hyke from the APSI, I attended in 2006. I have altered it and combined with LD-50 for this 5E)

Materials needed for serial dilution

As students walk through the procedure, fill in their data charts and answer the guiding questions, they hopefully will come up with the concept on their own–toxins can still be present even in very small amounts such as parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt). Materials needed are: (Click on an underlined item for a link to the product)

Dropper bottle of a dye/stain/coloring such as a Food Grade Dye like FD&C Red Dye #40 Do not use regular food coloring as it dilutes much too quickly

Students use 3-4 drops of the red dye solution in the first well. Then they fill the other wells with 9 drops of tap water. After that, they drop one drop from the previous well and stir.

Well Tray at the end of the lab

Students are often concerned when their solution is clear by well 7. I tell them that’s normal and they are to still make the transfers. They need to move the molecules in order to understand the point of the lab.

Students creatively identify shades of red and pink and learn about ppm, ppb, and ppt on their data sheet. Some students will need help with these circles. I tell them that “their brains will hurt” today.

Sample serial dilution data

Students using an online thesaurus to get creative on shades of red

Explain: Student Sense-Making

In a good 5E, students should be able to develop the concept you want them to on their own. Developing good guiding questions is your job as the teacher to lead them to it. For this lab, students should make a CLAIM or a STATEMENT that “Substances can be in water even if you cannot see it, smell it or taste it.

Elaborate: LC50 Lab

We use the results from the salinization Lab to do LC-50. Students bring their salinization labs back to class and we collect class data. (Students save all work in their APES binder) This time, however, we want “opposite” data–the number of seeds that DIED, instead of the number that germinated.

Students fill in the chart for their group’s data and then all students copy class data. I often make a chart on the board for groups to fill in.

From there, using a document camera or on the board, teach students how to find the LC-50 by drawing a line from 50% on the y axis to where it hits the dose-response curve and then down to the x axis. Read the concentration that kills 50% of seeds. If you need help with this, I made this video for absent kids that may help you understand how to do this lab:

Evaluate

This 5E does not have its own Evaluate–rather students are assessed for these skills and knowledge on their next exam.

* AP® is a trademark registered and/or owned by the College Board which was not involved in the production of, and does not endorse this site.

Take students outside to measure trees, discover ecosystem services of trees and forests, develop math skills, deforestation and sustainable forestry in the “I Love Trees 5E” Lab. If you are lucky enough to teach at a school next to a forested area, take the kids there. If not, trees on the school grounds, park or other area work just as well.

Student using a homemade clinometer to measure the height of a tree at school

Teacher Preparation

For this 5E, you need to make clinometers using cardboard, string/yard, a piece of metal (anything with a little weight) and a straw. You can have students make the clinometers if you would like, but I had my student lab assistant make 10 clinometers for me to save class time. They can be reused over and over. I made one clinometer for each group of 4 students.

Class set of clinometers that can be reused over and over

You also need two sewing tape-measures for each group of students and a tree map. I identified the trees ahead of time in the study area and googled their density. You could teach students how to identify trees using the iNaturalist app or a field guide if you want.

Materials for 1 group of students. One clinometer, two tape measures, and a tree map of the school grounds

Engage

An engage section of a 5E should be very short. For this 5E, I asked kids about the biggest tree they’ve ever seen. I find that personal questions where kids can share with their elbow partner and the rest of the class is very engaging. Another part of the Engage sections is review the photosynthesis equation–a good 5E builds on previous knowledge.

I show my own pictures with large trees (like Sequoias or Redwoods at the National Parks or large oak trees in town). Students like to see their teacher’s pictures.

This picture was taken 10 years ago in Sequoia National Park. My children are now older and one is in my APES class. Kids LOVE to see this.

Explore #1

Students head outside to take data in this Explore. Its helpful to demonstrate how to use the clinometer before heading outside. You or your students will choose a tree and measure the tree height using a homemade clinometer. They will also measure the tree circumference using the measuring tapes, the distance the tree to a building and the condition of the tree. After measurements, students will do math calculations using given formulas to help them determine the height, diameter, volume and mass (using the density), and the carbon sequestered by the tree.

Students hold the clinometer with the plumb line straight down and then walk forward or backwards until they can see through the straw to the top of the tree.

Students measure the circumference of the tree using measuring tapes and then use a formula to find the diameter.

Students use two measuring tapes to measure the distance from the tree to the student using the clinometer. The easiest way to do this is to “leapfrog” two tapes as shown above.

Explore #2

Students head back to class to enter their tree’s data on iTreeTools. Data chart for the results from iTree is below:

Total benefits for this year

$

Carbon Dioxide Sequestered

$

Annual CO2 equivalent of carbon

kg

Storm Water runoff avoided

$

Air Pollution Removed each year

$

Carbon monoxide removed

g

Ozone removed

g

Nitrogen Dioxide removed

g

Sulfur dioxide removed

g

Particulate matter < 2.5 microns removed

g

CO2 Stored to date

$

Life CO2 equivalent of carbon

kg

Explain: Student-Sense-Making

Students work through a series of questions to help them discover the scientific concept on their own. Sample questions:

What are the $ benefits of your tree? _________________

Review: What is the photosynthesis equation:

Draw a picture of the tree and show how molecules are moving

Where does the C from CO2 end up?

Think about it: How does cutting down trees for lumber and paper affect atmospheric carbon?

Think about it: How does cutting down trees and burning them affect atmospheric carbon?

Many species of trees increase in density, as they get older. How does this affect carbon sequestration? (Hint, the mass increases also).

Sample drawing for #3 above. The idea is for students to understand that carbon creates biomass in trees and other producers.

These and other questions help students discover the scientific concept/s and make a CLAIM. This is the place for formative assessment. Walk around and check student claims. Make sure they understand what you want them to understand.

Question ::How can how trees provide ecosystem services regarding climate change, air pollution and water pollution:

Claim :: (Complete sentence answer to the question above.—Make sure you write about ALL THREE ecosystem services)

Explain: New Understandings and Vocabulary

This is the place for formal science instruction. in this E, students will watch a series of 3 mini videos that describe more ecosystem services of trees and why tree-sitters do what they do. Students record more ecosystem services of trees on their lab report. Its best to do this portion as a class so that you can stop and discuss. However, it can be done at home, if needed, to save time. One video is a lovely TedTalk about trees.

Elaborate

In this section, students learn about deforestation and then sustainable forest solutions. Students will watch a series of 6 mini videos and fill in a T-chart with facts about deforestation and facts about sustainable forestry. Two sample videos are:

While there are some counter-arguments to sustainable forestry, students need to understand some solutions for exams. You can discuss places you agree or disagree with sustainable forestry.

Evaluate

The evaluate section of this 5E is unique, engaging and fairly easy to grade. Students will fill in the branches of the tree drawing with 5 ecosystem services:

Students then describe problems with deforestation next to the stump:

And methods of sustainable forestry next to this drawing:

The Evaluate section can be done individually or with a partner–with or without notes. You decide which is best for your students.

The basic concept of this lab is not complicated for students, but applying it to preserving biodiversity on continents or even thier own community can be counter-intuitive. Students have difficulty realizing that we have isolated habitats on land and that preserving pockets of habitat that are larger and closer together is the best for biodiversity.

The 5E Lab

This Island Biogeography Theory 5E Lab is inquiry-based to help students discover the concept on their own and develop critical thinking skills to make real-life applications.Engage: Students discuss how animals or plants migrate to islands.Explore: Students drop beans through funnels onto a poster multiple times and count the species that land on each island. They do some math to help them calculate averages per island.

Explain: Students make sense of their data using guiding questions and make a claim about the scientific concept–this is a great place for formative assessment. Then, they read a passage explaining the theory in formal academic and scientific vocabulary. Elaborate: Students apply this knowledge to isolated pockets of land in their community using Google Earth–its best to do this as a whole class so that you can help students find pockets of habitat. This is something that most students have never realized, but when they do, its a great “aha” moment. They then apply this knowledge to our National Parks. Using a map of the National Parks, they are asked which parks would have the most biodiversity using this theory and then where they would create a new park. Many students want to put a new park in a state (like Kansas) that doesn’t have any national parks. This is incorrect according to this theory. A large park next to an existing large park is the best solution according to this theory.

Evaluate: Students write a chunk paragraph addressing the following questions. They are to base their argument using evidence from this lab.

What do you
observe in your town about habitat fragmentation? What kind of wildlife would be the most
affected?

How could we
use this concept when we develop urban planning? How should development occur
to preserve the most species?

The labs on this post tend to be popular, because they cover a lot of topics within the lab, build skills, and/or are engaging. You don’t need to do all of them! I do about half of the ones listed below. Some labs have links for the write-ups.

A question new AP® Environmental Science teachers ask is “What supplies do I need?” or “What kits should I buy?” This post will go over basic APES lab supplies.

Kits are a great way to start and can help many new AP® teachers, but aren’t necessary if you don’t have the funds. Most labs can be sourced more cheaply by ordering individual items.

APES lab supplies can be cheap or expensive. What you decide to do depends on your location (some outdoor labs are regional), the materials you have, the size of your classes and how much money you have. Over time, apply for grants and other funding to build up your supply of plant lights, probesware etc.

You need basic lab supplies that your school should already have such as glass and plastic beakers, balances, graduated cylinders etc.

APES Lab Supplies for Must-do Labs

While there are no official required labs for APES, there are a few which have appeared on the AP® Exam or cover many concepts that have appeared on the exam. Here are some recommendations for APES lab supplies.

If you have a pond or creek to walk to, you may want a portable kit and a couple of hip waders and macroinvertebrate collection devices or kits.

Probes or sensors are more expensive initially, but end up saving money over multiple years. See this post for supply ideas for an in-class lab.

My favorite inexpensive dissolved oxygen meter is the Milwaukee Dissolved Oxygen Probe. It rarely needs calibration and lasts for years. Also, fairly inexpensive (for a DO meter) on Amazon.

Experimental Design Lab: Don’t do as a separate lab just to teach scientific method at the beginning of the year–you don’t have time in an AP® course. Instead, teach experimental design with another lab such as salinization, ocean acidification, biodiversity with quadrats, or air particulates.

One of the best (and easy to implement) labs I do is an air pollution lab–airborne particulates lab. I worked with a colleague at a neighboring school (Laura Solarez) to develop this lab for AP® Environmental Science.

Day 1

Day one of the air pollution lab takes about 45-60 minutes. Student lab groups brainstorm and come up with a question to test, a hypothesis, and design. They must get two approvals from me before making their petri dishes. My students have already done an experimental design lab so this process is fairly quick at this point. If this is the first experimental design lab of the year, expect this to take longer and for students to need more revision.

Student Sample

This lab is challenging with the constants. They can never really isolate all the variables and because of this, they will get flawed data. This is really important!! Analyzing the weaknesses in their lab help them identify flawed experiments later on in life and on the AP® Exam. I aim to develop scientifically literature citizens.

I give students some ideas such as comparing indoor vs. outdoor particulates, front yard vs. back yard or the number of pets. Some students come up with very creative ideas outside of these suggestions.

If rain is in the forecast, make sure they don’t set out the dishes in the rain (or sprinklers). Also, they need to make sure they all set out the dishes on the same day for the same amount of time, because weather can influence.

After approvals, students make their dishes. I made this video last year. They pay attention to the video more than me demonstrating in person! I show the video up to minute 3:18 on Day 1

Make sure you tell students to make a little sign at home, because I’ve had many dishes thrown away by parents over the years. They don’t know what it is and just throw away. Students make a sign that says “Science experiment–don’t throw away”.

Student making the dishes

Students label and bring dishes home to expose

A control dish that is not exposed indicates that the particulates came from the air, not the vaseline or were already in the dish.

Day 2 of the Lab

Day 2 of the air pollution lab is several days later. Give students enough time (over the weekend, for example) to expose their dishes for at least 24 hours. Students bring their dishes back to school on the day you instruct.

I show the rest of my video to help them understand how to count the particulates using stereoscopes. If you don’t have stereoscopes, you can use LED tap lights and hand lens.

Students need to make a template out of graph paper to use on each petri dish. Its impossible to count every particulate so using a template with a few boxes helps them manage the counting.

Students examining square #2 in stereoscope

Using a stereoscope

View through a stereoscope. Each black dot and line is a particulate

Since students work in groups of 4, they divide up tasks. Some count data and some begin their posters. They can switch jobs if they desire.

Counting particulates and making posters

Dividing up tasks

Sample poster

After students finish counting particulates, They can wash the dishes in hot soapy water and dry. The dishes can be used again next year and also for the Soil Salinization lab.

Assessment

I like students to make and present posters for this air pollution lab. It really helps them discuss and analyze the results. Why their hypothesis was correct or not AND more importantly, why this lab was flawed. They can never fully control all the variables and I want them to see that other factors may have influenced their results. This is the best part of the lab–learning to identify flawed experiments.

My poster template is inspired by Argument-Based Inquiry, but I have added more sections and clearer instructions.

I have had students present to the entire class, present to two other groups, or make a Flipgrid. All three ways have merit.

You can also have students write a formal lab report individual or as a group as assessment as well.

Water Quality Testing is essential for AP® Environmental Science students. Every released exam has water quality test questions.

Ideally, taking kids to a stream or pond is best, but testing water quality in the field is not possible for my students in arid Southern California. Surface water is seasonal and often too far away. Instead, my students bring in water samples to the lab.

Scroll to the bottom for links to student handouts.

Teaching Students to Collect a Water Sample

I demonstrate how to take a water sample for students. This year, I made a video which they enjoyed more than my demonstration.

Any empty bottle (water, Gatorade etc) works. Rinse out a little with the sample water and then fill under the water. Interesting water sources include rivers, creeks, ponds, lakes, well water, the ocean and fountains.

This student brought in a sample from a Disneyland fountain.

Ideally, students should wear gloves to collect the sample. But, if they forgot to bring gloves, they can throughly wash with warm water and soap after collecting the sample.

Students should cap the bottle under the water to prevent air at the top from skewing the dissolved oxygen (DO) results. Sometimes, this isn’t possible (with a small creek or heavy waves in the ocean) so I tell them to do the best they can. There is some error as Biological Oxygen Demand will decrease the DO reading, but we discuss this.

Students need to label the bottles and bring to class on the day we do water quality testing.

In the Lab

I used a LaMotte water quality testing kit the first year I taught APES, but soon realized that probeware was more economical in the long run with the quantity of students I have. I was accepted for grant funding to purchase my initial probeware and have used science funds and donation money to replace items as needed. Read where to find science funding.

Student using the Salinity Probe

I use a variety of water quality testing devices that are easy to use. I used to have a full set of Vernier probes, but over time they either broke or I stopped using them due to needing calibration–sometimes right in the middle of a lab! This collection is what I currently use–requires little prep work on my part and works for an entire day–5 sections of APES students.

These 9 baskets are rotated around the lab. Each basket has laminated instructions

I rotate baskets instead of kids going to stations. This is easier with 36 kids in lab and then they don’t have to travel with their water sample. I give kids about 4 minutes per basket and then they rotate clockwise. Kids also spend that time using reference sheets to see what the test measures and what are the levels for safe drinking water and for healthy aquatic life.

Water Quality Tests Reference Sheets

Water Quality Testing Devices

This is the LaMotte Testing kit I used before I received grant money to purchase my initial probeware 12 year ago.

Today, I use a variety of items that are reliable, economical for 165 kids in APES and easy to use. They’ve been acquired over a dozen years through various means and I’ve changed a few items over time. Most of them have links to Amazon if you want to read more about the item.